California Redistricting: Population Shifts Favor Republicans, for Now

We're still months away from having the results of the 2010 Census, but, in some ways, there isn't that much suspense. While it will ...

We're still months away from having the results of the 2010 Census, but, in some ways, there isn't that much suspense. While it will be exciting to learn precisely how many congressman and electoral votes each state receives, the basics of the population shifts that have taken place over the last ten years are clear.

One reason they're clear is that the Census Bureau produces annual estimates of how many people live in each state, city and county across the country. You probably already know the overall picture: The fastest growth is in generally Republican Sunbelt states (though the recession has stalled that trend to some extent).

For legislative redistricting, though, what matters are the intrastate population trends (they also matter quite a bit for congressional redistricting). The Bureau just released its most recent county numbers last month, which estimate the population as of July 1, 2009. From those, we can examine a key question: Is population growth in Democratic or Republican places?

I'm going to start by trying to answer that question in California and
(while I make no firm promises) I want to write about a lot more states
in the days and weeks ahead. Plus, you don't have to wait for me. If
you know where to look on the Census site for the population data, know the formula for percent change, know about Dave Leip's Atlas of U.S. Presidential Elections and have a basic knowledge of Excel, you can do this yourself.

Below, you'll see the population change from 2000 to 2009 in California's 22 most populous counties, as well as the performance of President Obama and 2006 Democratic gubernatorial nominee Phil Angelides in each of those counties. Together, these counties are home to more than 90% of Californians.

As you can see, the key Democratic bastions in California are San Francisco, Los Angeles County, Santa Clara County (home to San Jose) and Alameda County (home to Oakland). Each one of those counties has grown more slowly than the state as a whole over the last decade.

For Republicans to win in California, they have to score well in San Diego County, Orange County and the two counties of the Inland Empire: Riverside and San Bernardino. San Diego and Orange are growing somewhat more slowly than the state as a whole, but Riverside and San Bernardino are growing quite quickly.

In every county on this list with population growth over 10% in the last decade, Obama and Angelides performed worse than they did statewide. That's not too surprising. The traditional urban core of the state is most Democratic and it also has the least room to grow. That means that after redistricting more California legislators and congressman will represent areas that favor Republicans -- or at least areas that are more likely to favor Republicans than the state as whole.

But, here's another question: Why are these places growing? Who are the new people living there?

In San Bernardino and Riverside, a large share of the new residents are Hispanics. In 2000, Riverside and San Bernardino were 36.2% and 39.2% Hispanic, respectively. In 2008, Hispanics were 43.9% of the population in Riverside and 47.5% in San Bernardino. In other words, these two key counties are adding Hispanics far faster that they're adding whites. In fact, most of the population growth has been from Hispanics.

Hispanics, of course, generally vote Democratic. That San Bernardino County and Riverside County generally remain Republican-leaning (despite Obama's narrow wins in both places) probably reflects that many of these new Hispanic residents don't regularly vote. Many, no doubt, aren't U.S. citizens. Many more are children.

But, what about by 2016 or 2018 or 2020? Congressional and legislative districts in the area could lean Republican when they're drawn next year, only to slip out of the party's fingers over the course of the decade.

My expectation is that this will be one of the central themes of the Census: The most rapid growth is in Republican places, but, in many cases, it's among people who are likely to be Democratic voters. What that might mean is that this round of redistricting will produce short-term Republican gains, but, over the long haul, these Republican places won't be Republican anymore.